The invention relates to a stock (2; 3) of a repeating rifle with a connection region (21; 22) for connecting the stock (2; 3) to a system casing (1), with the connection region (21; 22) containing curved end connection surfaces (24; 34) for contacting correspondingly curved contact surfaces (9; 10) of the system casing (1) and the connection region (21; 22) having a recess (23; 33) tapering inward on the bottom side and a lower contact surface (28; 38) for contacting an upper support surface (16; 20) of the system casing (1). The invention further relates to a system casing for such a stock and a repeating rifle with such a system casing and stock.